Compounds useful in the treatment of anthrax and inhibiting lethal factor

ABSTRACT

This invention relates to compounds of formula (I), and a method for treating anthrax or inhibiting lethal factor by administrating a composition containing a compound of formula (I) and a pharmaceutically acceptable carrier. This invention further relates to the use of the compounds of formula (I) to treat other conditions related to an anthrax infection.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/US2003/016336 filed May 23, 2003 which claims the benefit under 35U.S.C. 119(e) of U.S. Provisional Application No. 60/383,996 filed onMay 29, 2002.

BACKGROUND OF THE INVENTION

The references cited throughout the present application are not admittedto be prior art to the claimed invention.

Anthrax is a bacterial infection produced by Bacillus anthracis.Bacillus anthracis endospores can enter the body through skin abrasions,inhalation, or ingestion. Bacillus anthracis produces an anthrax toxinthat is often lethal. (Dixon et al., (1999) N. Engl. J. Med. 341,815-26.)

Anthrax toxin consists of three proteins, a receptor-binding componentdesignated protective antigen, and two enzymatic components termed edemafactor and lethal factor (“LF”). (Mock et al., (2001) Annu. Rev.Microbiol. 55, 647-71.) Lethal factor is a zinc-dependentmetalloprotease that appears to exert toxic affects by cleavingmitogen-activated protein kinase kinases (MKKs). (Vitale et al., (1998)Biochem. Biophys. Res. Commun. 248, 706-11, Vitale et al., (2000)Biochem. J. 352 Pt 3, 739-45, Duesbery et al., (1998) Science 280,734-7, Duesbery et al., International Publication No. WO 99/50439,International Publication Date Oct. 7, 1999.)

Vitale and co-workers have used microsequencing to identify the site indifferent MKKs that are cleaved by lethal factor. (See Table 1, Vitaleet al., (2000) Biochem. J. 352 Pt 3, 739-45.) Lethal factor cleavage ofdifferent MKKs occurred within the N-terminal region preceding thekinase domain. Alignment of the sequences flanking the cleavage siterevealed some consensus motifs: a hydrophobic residue in position P2 andP1′, and at least one basic residue between P4 and P7. (Vitale et al.,(2000) Biochem. J. 352 Pt 3, 739-45.)

Lethal factor has been indicated to cleave synthetic peptides in vitro.(Hammond et al., (1998) Infect. Immun. 66, 2374-8.) In vitro cleavagewas inhibited by 1,10-phenanthroline or 10 mM EDTA, both of whichchelate zinc.

Bacillus anthracis is a spore forming gram-positive bacillus, which isthe etiologic agent of anthrax. Anthrax is a disease that can be foundglobally in temperate zones (e.g. South and Central America, South andEast Europe, Asia, Africa, Middle East, and Caribbean) and istransmissible to humans through handling or consumption of contaminatedanimal products (e.g. eating undercooked meat from infected animals).Wildlife mammals such as deer, wildebeest, elephants, and domesticatedlivestock, such as goats, sheep, cattle, horses, and swine are at highrisk for contracting the disease. Contraction generally occurs fromgrazing on contaminated land, eating contaminated feed or drinking fromcontaminated water holes. Bacillus anthracis spores can remain viable insoil for many years. See Helgason et al., Applied and EnvironmentalMicrobiology 2000 66(6) pgs. 2627-2630; Wber et al., Antimicrob Agentsand Chemotherapy 1988 32(5): 642-645; and Doganay et al., Scand. J. Inf.Dis. 1991 23:333-335 for further discussion of Bacillus anthracis.

In humans three forms of anthrax infections can occur, cutaneous,gastro-intestinal and inhalational. With the cutaneous form, infectionsoccur when the bacterium or spore enters a cut or abrasion on the skin.See Synder, J. W., Shapiro, D. S., Gilchrist, M. J. R., et al., “BasicDiagnostic Testing Protocols for Level A Laboratories (For ThePresumptive Indentification of Bacillus anthracis)” atwww.ban.asm.1a.cp.102401f, Oct. 24, 2001, pgs. 1-20 and Dixon, et al.,NEJM 341: 815-826 Sep. 9, 1999 Number 11. Symptoms of the skin infectionare generally raised itchy bumps or bump that resembles an insect bite.Within one to two days, the bumps or bump develops into a fluid-filledvesicle, which ruptures to form a painless ulcer with a characteristicblack necrotic (dying) area in the center. If left untreated, death canresult, however, deaths are rare if appropriate antibiotic therapy isadministered.

Gastrointestinal anthrax generally occurs from the consumption of meatcontaminated with the bacterium, which results in an acute inflammationof the intestinal tract. Signs of nausea, loss of appetite, vomiting,fever, along with abdominal pain, vomiting of blood and severe diarrheaare indicative of gastrointestinal anthrax. The mortality rate for thisform of human anthrax is estimated at 25%-60%.

Inhalation anthrax is most likely the result of intentional aerosolrelease of Bacillus anthracis, such as an act of bioterrorism. This formof human anthrax infection commonly has an incubation period of one tosix days, with fever, malaise, fatigue, a nonproductive cough and/ormild chest discomfort sometimes being the initial signals. These initialsymptoms are often followed by a short period of improvement, followedby the abrupt development of sever respiratory distress with laboredbreathing, perspiration and bluish skin color. Death usually occurswithin 24-36 hours after the onset of respiratory distress despiteaggressive treatment.

Most Bacillus anthracis strains are sensitive to a broad range ofantibiotics. The commonly prescribed therapies today are ciprofloxacin,penicillin, or doxycycline. However, the efficacy and side effectprofiles of these agents are not ideal.

While antibiotics can kill the bacteria that cause anthrax, thetripartite anthrax toxin continues to damage the body even when thebacteria themselves are dead. Therefore, there still exist the need fornew and effective therapies with improved efficacy, little or no sideeffect and which inhibit the scissor-like ability of lethal factor tosnip apart imprtant host molecules.

SUMMARY OF THE INVENTION

This invention relates to novel compounds of formula I:

or a pharmaceutically acceptable salt, enantiomer, diastereomer or invivo hydrolysable ester or mixture thereof, wherein,

-   R¹ represents C₆₋₁₀ aryl, C₅₋₁₀ heteroaryl or C₅₋₁₀ heterocyclic,    said aryl, heteroaryl and heterocyclyl optionally substituted with 1    to 3 groups of R^(a)-   R^(a) represents C₁₋₆ alkyl, halogen, OH, aryl(C₁₋₆)alkyl,    (C₁₋₆)alkoxy, (C₁₋₆)alkoxy(C₁₋₆)alkyl, halo(C₁₋₆)alkyl, nitro,    amino, mono- or di-N-(C₁₋₆)alkylamino, acylamino, acyloxy, carboxy,    carboxy salts, carboxy esters, carbamoyl, mono- and    di-N-(C₁₋₆)alkylcarbamoyl, (C₁₋₁₆)alkoxycarbonyl, aryloxycarbonyl,    ureido, guanidino, sulphonylamino, aminosulphonyl, (C₁₋₆)alkylthio,    (C₁₋₆)alkylsulphinyl, (C₁₋₆)alkylsulphonyl, heterocyclyl,    heterocyclyl(C₁₋₆)alkyl; and-   R represents C₁₋₈ alkyl, C₃₋₁₀ cycloalkyl, C₃₋₁₀ heterocycloalkyl,    C₅₋₁₀ heteroaryl, or C₅₋₁₁ heterocyclyl, said heteroaryl and    heterocyclyl optionally substituted with 1 to 3 groups of R^(a) and    said alky, optionally substituted with 1-3 groups selected from the    group consisting of aryl, heterocyclyl, (C₁₋₆)alkylthio, cyano,    heteroaryl, guanidino, ((1-aminoethyl)carbonyl)amino,    ((aminomethyl)carbonyl)amino, ((2-amino)prop-2-yl) carbonyl)amino,    acetamido, 4-(aminomethyl)phenyl, thio, t-butyl sulfonyl,    (C₂₋₆)alkenylthio, (C₂₋₆)alkynylthio, amino, mono- or    di-(C₁₋₆)alkylamino, arylthio, heterocyclylthio, (C₁₋₆)alkoxy,    aryl(C₁₋₆)alkoxy, aryl(C₁₋₆)alkylthio, cycloalkyl, cycloalkenyl,    carboxy and esters thereof, hydroxy and halogen.

This invention further relates to the use of the compounds of formula Iin the treatment of anthrax and other conditions, which are related toan anthrax infection.

This and other aspects of the invention will be realized upon inspectionof the invention as a whole.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to the compounds of formula I, and amethod for treating anthrax or inhibiting lethal factor byadministration, preferably intravenous or intra-muscular, of acomposition containing a compound of formula I and a pharmaceuticallyacceptable carrier.

The invention is described herein in detail using the terms definedbelow unless otherwise specified.

When any variable (e.g. aryl, heterocycle, R¹, R etc.) occurs more thanone time in any constituent, its definition on each occurrence isindependent at every other occurrence. Also, combinations ofsubstituents/or variables are permissible only if such combinationsresult in stable compounds.

The term “alkyl” refers to a monovalent alkane (hydrocarbon) derivedradical containing from 1 to 10 carbon atoms unless otherwise defined.It may be straight, branched or cyclic. Preferred alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl, t-butyl, cyclopentyl andcyclohexyl. When the alkyl group is said to be substituted with an alkylgroup, this is used interchangeably with “branched alkyl group”.

Preferably, alkenyl is C₂-C₆ alkenyl.

Preferably, alkynyl is C₂-C₆ alkynyl.

Cycloalkyl is a specie of alkyl containing from 3 to 15 carbon atoms,unless otherwise specified, without alternating or resonating doublebonds between carbon atoms. It may contain from 1 to 4 rings that arefused. Examples of cycloalkyl groups are cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, and cycloheptyl. Heterocycloalkyl is intendedto mean cycloalkyl ring groups which consists of carbon atoms and fromone to four heteroatoms selected from the group consisting of N, O, andS, and including any bicyclic. Said heterocycloalkyl can optionally besubstituted with 1 to 3 groups of R^(a) described herein. Examples ofHeterocycloalkyls are oxane, methyloxane, dioxane, pyran, thiolane,piperidine, pyrrolidine, aziridine, azetidine, etc.

Alkoxy refers to C₁-C₆ alkyl-O—, with the alkyl group optionallysubstituted as described herein. Examples of alkoxy groups are methoxy,ethoxy, propoxy, butoxy and isomeric groups thereof.

Halo is short for halogen and refers to chloride, fluoride, bromide andiodide.

As used herein, “aryl” is intended to mean any stable monocyclic orbicyclic carbon ring of up to 7 members in each ring, wherein at leastone ring is aromatic. Examples of such aryl elements include phenyl,naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl oracenaphthyl.

The term heterocyclyl or heterocyclic, as used herein, represents astable 5- to 7-membered monocyclic or stable 8- to 11-membered bicyclicheterocyclic ring which is either saturated or unsaturated, and whichconsists of carbon atoms and from one to four heteroatoms selected fromthe group consisting of N, O, and S, and including any bicyclic group inwhich any of the above-defined heterocyclic rings is fused to a benzenering. The heterocyclic ring may be attached at any heteroatom or carbonatom which results in the creation of a stable structure. A fusedheterocyclic ring system may include carbocyclic rings and need includeonly one heterocyclic ring. The term heterocycle or heterocyclicincludes heteroaryl moieties. Examples of such heterocyclic elementsinclude, but are not limited to, azepinyl, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,1,3-dioxolanyl, furyl, imidazolidinyl, imidazolinyl, imidazolyl,indolinyl, indolyl, isochromanyl, isoindolinyl, isoquinolinyl,isothiazolidinyl, isothiazolyl, isothiazolidinyl, morpholinyl,naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl, 2-oxopiperazinyl,2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl,pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl, pyrimidinyl,pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl,thienofuryl, thienothienyl, and thienyl. An embodiment of the examplesof such heterocyclic elements include, but are not limited to, azepinyl,benzimidazolyl, benzisoxazolyl, benzofurazanyl, benzopyranyl,benzothiopyranyl, benzofuryl, benzothiazolyl, benzothienyl,benzoxazolyl, chromanyl, cinnolinyl, dihydrobenzofuryl,dihydrobenzothienyl, dihydrobenzothiopyranyl, dihydrobenzothiopyranylsulfone, furyl, imidazolidinyl, imidazolinyl, imidazolyl, indolinyl,indolyl, isochromanyl, isoindolinyl, isoquinolinyl, isothiazolidinyl,isothiazolyl, isothiazolidinyl, morpholinyl, naphthyridinyl,oxadiazolyl, 2-oxoazepinyl, oxazolyl, 2-oxopiperazinyl, 2-oxopiperdinyl,2-oxopyrrolidinyl, piperidyl, piperazinyl, pyridyl, 2-pyridinonyl,pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl, pyrimidinyl,pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl,thienofuryl, thienothienyl, thienyl and triazolyl.

Preferably, heterocycle is selected from 2-azepinonyl, benzimidazolyl,2-diazapinonyl, imidazolyl, 2-imidazolidinonyl, indolyl, isoquinolinyl,morpholinyl, piperidyl, piperazinyl, pyridyl, pyrrolidinyl,2-piperidinonyl, 2-pyrimidinonyl, 2-pyrollidinonyl, quinolinyl,tetrahydrofuryl, tetrahydroisoquinolinyl, and thienyl.

As used herein, “heteroaryl” is intended to mean any stable monocyclicor bicyclic carbon ring of up to 7 members in each ring, wherein atleast one ring is aromatic and wherein from one to four carbon atoms arereplaced by heteroatoms selected from the group consisting of N, O, andS. Examples of such heterocyclic elements include, but are not limitedto, benzimidazolyl, benzisoxazolyl, benzofurazanyl, benzopyranyl,benzothiopyranyl, benzofuryl, benzothiazolyl, benzothienyl,benzoxazolyl, chromanyl, cinnolinyl, dihydrobenzofuryl,dihydrobenzofuranyl, dihydrobenzothienyl, dihydrobenzothiopyranyl,dihydrobenzothiopyranyl sulfone, furyl, imidazolyl, indolinyl, indolyl,isochromanyl, isoindolinyl, isoquinolinyl, isothiazolyl, naphthyridinyl,oxadiazolyl, pyridyl, pyrazinyl, pyrazolyl, pyridazinyl, pyrimidinyl,pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl,tetrahydroisoquinolinyl, tetrahydroquinolinyl, thiazolyl, thienofuryl,thienothienyl, thienyl and triazolyl.

In one embodiment of this invention relating to the compounds of formulaI R is a heterocycloalkyl and all other variables are as originallydescribed.

In another embodiment of this invention relating to the compounds offormula I R is a heteroaryl and all other variables are as originallydescribed.

In still another embodiment of this invention relating to the compoundsof formula I R¹ is a phenyl group optionally substituted with 1-3 groupsof R^(a) and R is a heterocycloalkyl, or heteroaryl group.

In yet another embodiment of the invention relating to the compounds offormula I R¹ is a phenyl group substituted with 1 to 3 groups ofmethoxy, halogen, methyl, ethyl, propyl, butyl, napthyl,5-(2-pyridyl)thiophen-2-yl or a mixture thereof, and R aheterocycloalkyl or heteroaryl.

In yet another embodiment of this invention relating to the compounds offormula Ia R is a heterocycloalkyl and all other variables are asoriginally described.

In another embodiment of this invention relating to the compounds offormula Ia R is a heteroaryl and all other variables are as originallydescribed.

In another embodiment of this invention relating to the compounds offormula Ia R is a C₁₋₄ alkyl and all other variables are as originallydescribed.

In still another embodiment of this invention relating to the compoundsof formula Ia R¹ is a phenyl group optionally substituted with 1-3groups of R^(a) and R is an alkyl, heterocycloalkyl, or heteroarylgroup.

In yet another embodiment of the invention relating to the compounds offormula Ia R¹ is a phenyl group substituted with 1 to 3 groups ofmethoxy, halogen, methyl, ethyl, propyl, butyl, napthyl,5-(2-pyridyl)thiophen-2-yl or a mixture thereof, and R is an alkyl,heterocycloalkyl or heteroaryl.

Another embodiment of this invention relates to a pharmaceuticalcomposition comprising a compound of formula I and a pharmaceuticallyacceptable carrier.

Another embodiment of this invention involves the use of a compound offormula I for the production of a medicament for the treatment orprophylaxis of anthrax and conditions related thereto. Still anotherembodiment involves the use of a compound of formula I for theproduction of a medicament for inhibiting lethal factor.

The compounds of formula I may be combined with one or more known drugsselected from clinically useful antibacterial agents (for example otherbeta-lactams or aminoglycosides), inhibitors of beta-lactamase, renaltubular blocking agents (e.g. probenecid) and inhibitors of metabolisingenzymes (for example inhibitors of dehydropeptidases, for exampleZ-2-acylamino-3-substituted propenoates such as cilastatin) andN-acylated amino acids (for example see EP-A-178911) which reduceadverse effects on the kidney. Examples of drugs that can be combinedwith the compounds of formula I are imipenem, meropenem, vancomycin,cilastatin, cefoxitin, penicillin, clavulanic acid, probenecid,tetracycline, ciprofloxacin, norfloxacin or a mixture thereof. It ispreferred that when imipenem is used as a drug it is used in combinationwith cilastatin (said combination is marketed as PRIMAXIN®).

Suitable pharmaceutically acceptable salts of the compounds used in thisinvention include acid addition salts such as hydrochloride,hydrobromide, citrate, maleate and salts formed with phosphoric andsulphuric acid. In another aspect suitable salts are base salts such asan alkali metal salt for example sodium or potassium, an alkaline earthmetal salt for example calcium or magnesium, an organic amine salt forexample triethylamine, morpholine, N-methylpiperidine,N-ethylpiperidine, procaine, dibenzylamine, N,N-dibenzylethylamine oramino acids for example lysine. Preferred pharmaceutically acceptablesalts are sodium and potassium salts.

In vivo hydrolysable esters are those pharmaceutically acceptable estersthat hydrolyze in the human body to produce the parent compound. Suchesters can be identified by administering, e.g. intravenously to a testanimal, the compound under test and subsequently examining the testanimal's body fluids. Suitable in vivo hydrolysable esters for carboxyinclude C1-6alkoxymethyl esters for example methoxymethyl, C1-6alkanolyloxymethyl esters for example pivaloyloxymethyl, phthalidylesters and the additional esters disclosed in U.S. Pat. No. 5,478,820,which is herein incorporated by reference in its entirety.

Compounds used in this invention are:

-   N-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide;-   N-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-(S)-cyclopropylbutyramide;    and pharmaceutically acceptable salts, enantiomers, diastereomers or    in vivo hydrolysable esters or mixtures thereof.

Additional compounds of this invention are disclosed in Table 1:

TABLE 1

Example # R1 R2 3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

and pharmaceutically acceptable salts, enantiomers, diastereomers or invivo hydrolysable esters or mixtures thereof.

Still other compounds of this invention are disclosed in Table 2:

TABLE 2

Example # R1 R2 146

Me 147

Me 148

Me 149

H 150

Me 151

Me 152

Me 153

Meand pharmaceutically acceptable salts, enantiomers, diastereomers or invivo hydrolysable esters or mixtures thereof.

Preferred compounds used in this invention are:

-   N-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide;-   N-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide;-   N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-(S)-cyclopropylbutyramide;    and pharmaceutically acceptable salts, enantiomers, diastereomers or    in vivo hydrolysable esters or mixtures thereof.

In order to use a compound of formula I or a pharmaceutically acceptablesalt, enantiomer, diastereomer or in vivo hydrolysable ester or mixturethereof for the therapeutic treatment of mammals, including humans, inparticular in treating anthrax, or inhibting lethal factor it isnormally formulated in accordance with standard pharmaceutical practiceas a pharmaceutical compositon.

The compounds used in the instant invention can be administered in atherapeutically effective amount intravaneously, subcutaneously,intramuscularly or any other method known to those skilled in the art(e.g., rectal, oral, parenteral). A suitable pharmaceutical compositionused in this invention is one, which is made for sterile injectioncontaining between 1 and 50% w/w of the compounds used in thisinvention.

Suitable subjects for the administration of the formulation of thepresent invention include primates, man and other animals, particularlyman and domesticated animals such as cats, rabbits and dogs.

The following non-limiting examples, given by way of illustration, isdemonstrative of the present invention, that the compounds used in thisinvention are useful for treating anthrax and inhibiting lathal factor.

Definition of terms are:

-   HOBT—hydroxybenzotriazole-   DMF—dimethylformamide-   DIEA—diisopropylethylamine-   TMSONH2—O-trimethylsilylhydroxylamine-   PyBOP—bnezotrizole-1-yl-oxy-tris-pyrrolidino-phosphonium    hexafluorophosphate-   TFA—trifluoroacetic acid-   HPLC—high performance liquid chromatography-   DCM—dichloromethane-   EDC—1-(3-dimethylaminopropyl)-3-ethylcarbodiimide-   THF—tetrahydrofuran-   DIC—N,N′-diisopropylcarbodiimide-   MDF—dimethylformamide-   DMAP—4-dimethylaminopyridine-   NMP—1-methyl-2-pyrrolidinone-   EDTA—ethylenediaminetetraacetic acid

EXAMPLE 1

N-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide(1.8 g, 4.99 mmol) was dissolved in 75 ml of anhydrous dichloro-ethanecontaining ethanol (0.30 ml, 5 mmol) at 0° C. Hydrogen chloride gas wasbubbled in for 30 min. The flask was closed with a septum and reactionmixture stirred for 2 days. After the solvent was removed on a rotavap,the residue was dissolved in methanol (1˜2 ml), and diluted with DCM (20ml). The crystals formed were collected and washed with more DCM togive, after vacuum drying,N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramide.NMR (500 MHz, CD₃OD) δ: 0.86 (d, 3H), 0.91 (d, 3H), 1.86 (m, 1H), 2.30(d, 3H), 3.30 (d, 1H), 7.16 (t, 1H), 7.67 (m, 1H), 7.72 (m, 1H).

The starting material for example 1 was prepared as follows:

D-Valine (1.39 g, 11.9 mmol) was dissolved in 80 ml of dioxane/water(1:1) containing K₂CO₃ (3.3 g, 24 mmol). A solution of4-fluro-3-methylphenyl-sulfonylchloride (10 mmol) in dioxane (4 ml) wasdropped in with good stirring. The reaction mixture was stirred at roomtemperature for 30 min. Ethylacetate (80 ml), 1N HCl (50 ml) was added.The organic layer was washed with 1N HCl 2 times, and extracted with 5%K₂CO₃ (3×25 ml). The combined base extracts was acidified and extractedwith ethylaceate (80 ml). The organic layer was washed with brine (2×),dried over Na₂SO₄. The solvent was removed on rotavap, and residuetritrated with hexane. The resulting solid was dried to give2(R)-[(4-fluoro-3-methylphenyl-sulfonyl)]amino-3-methylbutyric acid.

2(R)-[(4-Fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyric acid (2.64g, 9.12 mmol) was dissolved in DCM (30 ml), followed by addition of DIEA(3.18 ml, 2 eq.) and O-t-butylhydroxylamine hydrochloride (2.3 g, 2eq.). EDC.HCl (2.1 g, 1.2 eq.) was then added portionwise as solid. MoreEDC (0.6, 0.5 eq.) was added after 40 min and the reaction was stirredfor another 30 min. The solvent was removed on a rotavap at roomtemperature, and residue was partitioned with ethylacetate (80 ml), 1NHCl (50 ml). The organic layer was washed with 1N HCl, brine, and driedover Na₂SO₄. The crude product was flash column purified with 5% to 12%ethylacetate in DCM gradient solvent to give productN-t-butoxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramideas a white foam. TLC (1:10 ethylaceate:DCM) Rf 0.16. NMR (500 MHz,CD₃OD) δ: 0.89 (d, 3H), 0.90 (d, 3H), 1.08 (s, 9H), 1.86 (m, 1H), 2.30(d, 3H), 3.44 (d, 1H), 7.18 (t, 1H), 7.70 (m, 1H), 7.77 (m, 1H).

EXAMPLE 2

Example 2,N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]-amino-2-(4′-tetrahydropyranyl)-acetamide,was prepared from D-4′-tetrahydro-pyranylglycine in the same way asexample 1. NMR (500 MHz, CD₃OD) δ: 1.19 (m, 1H), 1.34 (m, 1H), 1.40 (m,1H), 1.74(m, 1H), 1.80(m, 1H), 2.32 (d, 3H), 3.31 (m, 2H), 3.37 (d, 1H),3.90 (m, 2H), 7.18 (t, 1H), 7.65 (m, 1H), 7.72 (m, 1H).

EXAMPLE 3 TO 144

Examples 3 to 144, found in Table 1, were made on solid phase and isillustrated as follows:

Step 1. Resin Functionalization

A solution of N-hydroxyphthalimide (2.8 g, 17 mmol), DIEA (3.0 ml, 17mmol) in dichloromethane (30 ml) and DMF (15 ml) was added quickly to4.39 g of 2-Chlorotrityl resin (1.1 mmol/g loading) in a frit fittedcartridge. The resin suspension was shaken intermittently and left onbench overnight. The resin was washed 5× with DMF, and then treated witha 40 ml of hydrazine solution (0.5 M in THF) for 2 hr. A large amount ofwhite solid formed around the resin. It was washed with DMF-H₂O (1:1)2×, DMP 4×. The hydrazine treatment was repeated once more for another 3hours. The resin was washed with DMF-H₂O (1:1) 2×, DMF 4×, DCM 5×, driedin vacuum overnight to give 4.53 g of resin 1. The loading is about 1.0mmol/g by weight change.

Step 2. Loading of Amino Acid

The O-anchored hydroxylamine resin 1, 500 mg (˜1.0 mmol/g loading), wasswelled with DCM in a frit fitted cartridge and drained. A solution ofFmoc-D-allo-isoleucine (530 mg, 1.5 mmol, 3 eq.), DIC (0.120 ml, 0.75mmol, 1.5 eq.) in 3 ml of DMF was added. The cartridge was shakenbriefly and left on bench for 1 hr. Another dose of DIC (0.04 ml, 0.25mmol, 0.5 eq.) was added. After another hour, the resin was washed withDMF 4×, DCM 4× and vacuum dried overnight to give resin 2. Theapproximate loading is 0.70 mmol/g by weight gain.

Step 3

Resin 2, 150 mg, ˜0.7 mmol/g loading, was treated with 2 ml ofpiperidine/DMF (25%) for 2 hr. The resin was washed with MDF 3×, DCM 3×.A solution of DIEA (73 ul, 0.42 mmol, 4 eq.) in THF-DCM (1:1, 0.5 ml)containing DMAP (−2 mg) was added to the resin, followed by a solutionof 3-chlorophenylsulfonyl chloride (66 mg, 3 eq.) in THF-DCM (0.5 ml).After 3 hr, the resin was washed with DMF 3×, DCM 3×, and cleaved twicewith 5% TFA/DCM (0.5 ml) for 30 min. The combined cleavage solution wasevaporated, and the residue dissolved in CH₃CN:H₂O and purified on areverse phase BPLC to give Example 25,N-hydroxy-2(R)-(3-chlorophenylsulfonyl)amino-3(S)-methylvaleric amide.NMR (500 MHz, CD₃OD) δ: 0.82 (d, d, 6H), 1.04 (m, 1H), 1.35 (m, 1H),1.64 (m, 1H), 3.52 (d, 1H), 7.50 (t, 1H), 7.60(d, 1H), 7.76(d, 1H), 7.84(m, 1H).

Table 1 lists structures of examples 3 to 144. As can be appreciated bythe ordinary skilled artisan, Examples 4 to 144 were made, with somemodification, in accordance with the description provided for example 3.Some compounds required a de-protection step (treatment with 50%TFA/DCM) after cleavage off the resin.

EXAMPLE 145

2-(R)-[(4-fluro-3-methylphenyl)sulfonyl]amino-3-(S)-cyclopropyl-butyricacid (10 mg, 31 mmol) was dissolved in DMF (0.3 ml) with HOBt (4.5 mg,0.031 mmol), DIEA (11 ul, 0.062 mmol), O-trimethylsilylhydroxylamine (20ul, 0.16 mmol). A solution of PYBOP (20 mg, 0.038 mmol) in DMF (0.3 ml)was added. The reaction was quenched after 30 min with CH₃CN:H₂O (1:1,5% TFA) and passed through reverse phase HPLC to give, afterlyophilization,N-hydroxy-2-(R)-[(4-fluro-3-methylphenyl)sulfonyl]amino-3-(S)-cyclopropylbutyramide.NMR (500 MHz, CD₃OD) δ: −0.04 (m, 1H), 0.20 (m, 1H), 0.35 (m, 1H), 0.41(m, 1H), 0.54 (m, 1H), 0.90 (d, 3H), 1.08 (m, 1H), 2.32 (d, 3H), 3.60(d, 1H), 7.17 (t, 1H), 7.68 (m, 1H), 7.75 (m, 1H). MS: 331.1(M+H⁺).

The starting material for example 145 was prepared as follows:

Methyl glycolate (10.4 g, 114 mmol), crotyl alcohol (100 ml, excess),was refluxed in the presence of K₂CO₃ (0.8 g) for 1 hr, during whichtime about 10 ml of the condensate was removed through a Dean-Stocktrap. After diluting with hexane (100 ml), the solid was filteredthrough a short silica gel column (50 g), washed with 1:5ethylacetate:hexane (250 ml). The combined filtrate and washings wasconcentrated to 100 ml, and was diluted again with hexane (100 ml),passed through silica gel column and washed. The solution wasconcentrated to ˜12.5 g of oil, which was vacuum distilled to givecrotyl glycolate: 9.3 g (97° C./20 mmHg) as a mixture of cis:trans(1:10). NMR (500 MHz, CDCl₃) δ: 1.3 (m, 3H), 4.15 (s, 2H), 4.62 (d, 2H),5.6 (m, 1H), 5.84 (m, 1H). cis isomer: 1.71 (m, 3H), the rest peaksoverlaps with trans isomer.

The above made crotyl glycolate (9.3 g, 71 mmol) in THF (10 ml) wasadded slowly to a solution of LiN(TMS)₂ (200 ml, 1.0 M) in THF (200 ml)at −78° C. After 40 min at this temperature, trimethylsilyl chloride(25.5 ml, 200 mmol) was added. The cooling bath was removed and thereaction was stirred overnight. The reaction mixture was concentrated to˜150 ml and diluted with ethylacetate (500 ml). This was washed with 2NHCl twice. The washings were back extracted with more ethylacetate. Thecombined organic layer was extracted with 5% K₂CO₃ 3×. The combined basesolution was acidified with cold concentrated HCl, extracted withethylacetate. The ethylacetate solution was washed with saturated NaCl,dried over Na₂SO₄. Evaporation of solvent and vacuum drying gave2-hydroxy-3-methylpropen-4-enoic acid as a mixture of diastereomers. NMR(500 MHz, CD₃OD) for diastereomer 1 [(2R, 3S) and (2S, 3R)] δ: 1.02 (d,3H), 2.60 (m, 1H), 4.05 (d, 1H), 5.02 (m, 1H), 5.09 (m, 1H), 5.87 (m,1H); diasteteomer 2 [(2R, 3R) and (2S, 3S)] δ: 1.11(d, 3H), 2.6 (m, 1H),4.03 (d, 1H), 5.0 (m, 1H), 5.09 (m, 1H), 5.80 (m, 1H). Diastereomericratio by NMR is about 7 to 1 with diasteromer 1 as the major.

The above made acid (8.5 g, 65 mmol) was disolved in dry DMF (100 ml)and DIEA (16 ml, 91 mmol). Methyl iodide (11.7 ml, 85 mmol) was added.This was stirred for 15 hr, and diluted with ethylacetate (500 ml),washed with 0.1N HCl 3×, brine 2×, dried over Na₂SO₄. Evaporation ofsolvent left Methyl 2-hydroxy-3-methylpenten-4-enoic ester. NMR (500MHz, CD₃OD) for diastereomer 1 [(2R, 3S) and (2S, 3R)] δ: 1.02 (d, 3H),2.55 (m, 1H), 3.70 (s, 3H), 4.04 (d, 1H), 5.02 (m, 1H), 5.06 (m, 1H),5.81 (m, 1H); diasteteomer 2 [(2R, 3R) and (2S, 3S)] δ: 1.08 (d, 3H),2.58 (m, 1H), 3.70 (s, 3H), 4.07 (d, 1H), 5.00 (m 1H), 5.06 (m, 1H),5.80 (m, 1H).

The above made methyl ester (2.9 g, 20 mmol) was disolved in dry DCM(100 ml) with diiodomethane (8.1 ml, 100 mmol), and cooled to 0° C. Asolution of diethylzinc (100 ml, 1.0 M in hexane) was added. The coolingbath was removed and the mixture was stirred under nitrogen for 3 days.A solution of NH₄Cl was added to quench the reaction. The organic layerwas washed with HCl 2×, brine 2×, and dried over Na₂SO₄. Evaporation ofsolvent left oil containing 70% of product methyl2-hydroxy-3-cyclopropylbutyrate and 30% of starting material. It wasused without further purification.

A solution of the above made ester (3 g, 20 mmol), pyridine (2.0 ml, 24mmol) in dry DCM (10 ml) was slowly added to a stirred solution of Tf₂O(4.0 ml, 24 mmol) in DCM (100 ml) at 0° C. After 1 hr at 0° C., waterwas added to quench the reaction. This was then washed with dilute HCl(0.1 N), brine, and dried over Na₂SO₄. Evaporation of solvent gave 5.3 gof triflate as an oil. This was stirred with NaN₃ (2.4 g, 36 mmol) inDMF (80 ml) for 15 hr. The reaction mixture was diluted withethylacetate (400 ml), washed with dilute HCl 3×, brine 2×, dried overNa₂SO₄. Evaporation of solvent lfet 2.96 g of oil. Flash columnchromatography though silica gel, eluting with 5% ether in hexane gavemethyl 2-azido-3-cyclopropyl-butyrate as a colorless oil. The desireddiastereomer 1 [(2R, 3S) and (2S, 3R)] can be isolated throughpreparative reverse phase HPLC eluting with CH₃CN:H₂O gradient solvent.NMR (500 MHz, CDCl₃) for diastereomer 1 [(2R, 3S) and (2S, 3R)] δ: 0.04(m, 1H), 0.18 (m, 1H), 0.48 (m, 2H), 0.74 (m, 1H), 1.09 (d, 3H), 1.35(m, 1H), 3.80 (s, 3H), 3.92 (d, 1H).

The above isolated azide [(2R, 3S) and (2S, 3R)] diastereomer (400 mg,2.2 mmol) was dissolved in MeOH (10 ml), cooled in a water bath at 20°C. Stannous chloride (860 mg, 4.4 mmol) waw added. This was stirred for15 hr. To the the reaction mixture was added with dioxane (10 m10),K₂CO₃ (1.5 g 10.1 mmol)/H₂O (10 ml). The solid was filtered, washed withdioxane (5 ml). To the combined filtrate and washings was added asolution of 4-fluoro-3-methylphenylsulfonyl chloride (560 mg, 2.4 mmol)in dioxane (5 ml). About 30 min later, the reaction was acidified withHCl to pH 3, diluted with CH₃CN:H₂O. The product was isolated throughpreparative reverse phase HPLC (repeated injections) to Methyl2-(4-fluro-3-methylphenylsulfonamido)-3-cyclopropylbutyrate. Furtherseparation through Chiralpk column AD eluting with 7% EtOH in heptanegave two enantiomers, with the desired isomer 1 (2R, 3S) eluted outfirst. NMR (500 M, CD₃OD) δ: 0.01 (m, 2H), 0.39 (m, 2H), 0.62 (m, 1H),1.01 (d, 3H), 1.19 (m, 1H), 2.312 (d, 3H), 3.23 (s, 3H), 3.90 (d, 1H),7.18 (t, 1H), 7.68 (m, 1H), 7.73 (m, 1H).

Methyl2(R)-[(4-fluro-3-methylphenyl)sulfonyl]amino-3-(S)-cyclopropyl-butyricester (20 mg, 0.061 mmol) was dissolved in MeOH (0.2 ml), followed byaddition of LiOH (8 mg, excess)/H₂O (0.15 ml). After 2 hr the reactionwas acidified with 1.5 ml of CH₃CN:H₂O (1:1, 5% TFA) and chromatographedwith reverse phase HPLC to give2-(R)-(4-fluro-3-methylphenyl-sulfonamido)-3-(S)-cyclopropylbutyrc acid.NMR (500 MHz, CD₃OD) δ: −0.01 (m, 1H), 0.15 (m, 1H), 0.40 (m, 2H), 0.65(m, 1H), 1.02 (d, 3H), 1.22 (m, 1H), 2.31 (d, 3H), 4.83 (d, 1H), 7.16(t, 1H), 7.69 (m, 1H), 7.75 (m, 1H).

EXAMPLE 146

2(R)-[(4-Fluoro-3-methylphenyl)sulfonyl]amino-3(R)-cyclopentoxylbutyricacid (11 mg, 0.03 mmol) was dissolved in DMF (200 ul) with DEA (12 ul,0.12 mmol), HOBt (8 mg, 0.06 mmol), and TMSONH₂ (10 ul, 0.08 mmol). Asolution of PyBOP (31 mg, 0.06 mmol) in DMF (100 ul) was added. Thereaction was quenched after 20 min with 5% TFA/H₂O, and product isolatedfrom reverse phase HPLC to give, after lyophilization,N-hydroxy-2(R)-[(4-fluoro-3-methylphenyl)sulfonyl]amino-3(R)-cyclopentoxylbutyramide.NMR (500 MHz, CD₃OD) δ: 0.97 (d, 3H), 1.44-1.68 (m, 8H), 2.32 (d,J_(H-F), 3H), 3.61 (d, 1H), 3.72 (m, 1H), 3.67 (m, 1H), 7.18 (m, 1H),7.70 (m, 1H), 7.76 (m, 1H).The starting material for example 146 was prepared as follows:

N-Trityl-D-threonine benzyl ester (2.5 g, 5.5 mmol), TEA (2.8 ml, 20mmol) were dissolved in 100 ml of dry toluene at −50° C. A solution ofsulfuryl chloride (800 ul, 8 mmol) in toluene (20 ml) was added in 15min. The reaction was allowed to warm up to r.t. Ethylacetate (100 ml)was added and this was washed with sat. NaCl, dried over Na₂SO₄. Theproduct was crystallized in MeOH (10 ml) to give benzylN-trityl-3(S)-methylaziridine-2(R)-carboylate. NMR (500 MHz, CDCl₃) δ:1.37 (d, 3H), 1.64 (m, 1H), 1.95 (d, 1H), 5.15(d, J=12 Hz, 1H), 5.28(d,J=12 Hz, 1H), 7.19˜7.28 (m, 12H), 7.33˜7.36 (m, 1H), 7.36˜7.39 (m, 3H),7.51˜7.54 (m, 4H).

Benzyl N-trityl-3(S)-methylaziridine-2(R)-carboxylate, (2.13 g, 4.92mmol) was dissolved in 20 ml of MeOH:DCM (1:1) at 0° C., followed byaddition of TEA (20 ml). After stirring at room temperature for 1 hr,the excess reagent and solvent were removed on rotavap (T<25° C.). Theresidue was partitioned with DCM (50 ml) and H₂O (100 ml). The aqueousphase was washed once with DCM, and pH was adjusted to basic with NaHCO₃extracted with ethylacetate, and dried over Na₂SO₄. Removal of solventleft 650 mg of Benzyl 3(S)-methylaziridine-2(R)-carboxylate. This wasdissolved in DMF (15 ml) at 0° C. TEA (2.1 ml, 15 mmol) was added,followed by Boc₂O (1.64 g, 7.5 mmol). The reaction was stirred at roomtemperature overnight. Ethylacetate (100 ml), H₂O (100 ml) were added,and the organic layer was washed with 10% citric acid twice, brine, anddried over Na₂SO₄. The crude product was flash column chromatographed,eluting with 5% 10% EA/hexane gradient solvent containing 0.1% TEA, togive benzyl N-Boc-3(S)-methylaziridine-2(R)-carboxylate. NMR (500 M,CD₃OD) δ: 1.21(d, 3H), 1.44(s, 9H), 2.82 (m, 1H), 3.21(d, 1H), 5.2 (q,2H), 7.30˜7.38(m, 5H).

Benzyl N-Boc-3(S)-methylaziridine-2(R)-carboxylate (50 mg, 0.17 mmol),cyclopentyl alcohol (0.5 ml, 5.5 mmol) were dissolved in DCM (0.5 ml),followed by a few drops of BF₃.Et₂O. This was stirred at r.t. for 10 hr.The solvent was removed, and the residue purified through a reversephase HPLC. The product was collected and treated with 50% TFA/DCM togive benzyl 2(R)-amino-3(R)-cyclopentoxylbutyrate triflruoroacetate. NMR(500 MHz, CD₃OD) δ: 1.28 (d, 3H), 1.4˜1.7 (m, 8), 3.92 (m, 1H), 4.06 (d,1H), 4.14 (dq, 1H), 5.26 (d, J=12 Hz, 1H), 5.31 (d, J=12 Hz, 1H), 7.38(m, 3H), 7.43 (m, 2H).

Benzyl 2(R)-amino-3(R)-cyclopentoxylbutyrate triflruoroacetate (63 mg,0.16 mmol), DIEA (174 ul, 1.0 mol), DMAP (1 mg) were dissolved indioxane (2 ml), followed by slow addition of a solution of4-fluoro-3-methylphenylsulfonyl chloride (˜0.33 mmol) in dioxane (1 ml).After 15 min, the reaction was quenched with 5% TFA/H₂O, and purifiedthrough reverse phase HPLC to give benzyl2(R)-[(4-Fluoro-3-methylphenyl)sulfonyl]amino-3(R)-cyclopentoxylbutyrate.The benzyl ester protection group was removed by hydrogenation inMeOH:EA (1 ml) with 10% Pd/C (2 mg) overnight to give2(R)-[(4-Fluoro-3-methylphenyl)-sulfonyl]amino-3(R)-cyclopentoxylbutyricacid.

With some modification known to those skilled in the art, Examples 147to 153 of Table 2 were made in accordance with Example 146.

Assay for Determining Lethal Factor Inhibition

The assay below is disclosed in Cummings et al., PNAS, May 14, 2002,vol. 99, no. 10, page 6603-6606 and PCT Application US03/05552, filedFeb. 21, 2003 (U.S. Patent Application Ser. No. 60/359,707, filed Feb.25, 2002), incorporated herein by reference in their entirety. It isused to determine lethal factor inhibition after being reacted with acompound believe to be an inhibitor of lethal factor.

Lethal factor inhibitor compounds can be used to further study lethalfactor activity, and those inhibitory compounds having appropriatepharmacological properties can be used to help treat or prevent Anthrax.Appropriate pharmacological properties include efficacy, metabolism andabsence of unacceptable side effects.

High throughput screening for lethal factor inhibitors can be used toscreen large number of compounds to identify those affecting lethalfactor activity. High throughput screening is facilitated by an assaythat is readily automated and utilizes low levels of purified enzyme.

Measuring Activity

Lethal factor substrates can be used in methods measuring Bacillusanthracis lethal factor activity and the effect of a compound on suchactivity. Such methods involve incubating a lethal factor substratedescribed herein with Bacillus anthracis lethal factor using anincubation medium where the Bacillus anthracis lethal factor is active,and can include the presence of a compound being tested. Cleavage of thesubstrate can be detected as a measure of Bacillus anthracis lethalfactor activity or the effect of a compound on lethal factor activity.Measuring can be qualitative or quantitative. The lethal factor enzymebinding assay IC50 results for the compounds of this invention rangefrom 15 uM or less. Specifically the IC50 forN-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-3-methylbutyramideandN-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydopyranyl)-acetamideare 0.13 uM and 0.06 uM respectively.

1. A compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein: R¹ is selectedfrom the group consisting of C₆₋₁₀ aryl groups, said aryl groupsoptionally substituted with 1 to 3 groups of R^(a); R^(a) is selectedfrom the group consisting of C₁₋₆ alkyl and halogen groups; and R isselected from the group consisting of C₃₋₁₀ heterocycloalkyl groups. 2.The compound according to claim 1, wherein R¹ is a phenyl groupoptionally substituted with 1 to 3 groups of R^(a).
 3. The compoundaccording to claim 1, wherein R¹ is a phenyl group substituted with 1 to3 groups of halogen, methyl, ethyl, propyl, butyl, or a mixture thereof.4. The compound according to claim 1, wherein the compound is selectedfrom the group consisting of:N-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide; compounds provided in Table 1 below TABLE 1

Example # R₁ R₂ 64

74

78

105

130

and a pharmaceutically acceptable salt thereof.
 5. The compoundaccording to claim 4, wherein the compound isN-hydroxy-2(R)-[(4-fluoro-3-methylphenylsulfonyl)]amino-2-(4′-tetrahydropyranyl)-acetamide; or a pharmaceutically acceptable salt thereof.
 6. Acomposition comprising a compound according to claim 1 and apharmaceutically acceptable carrier.
 7. A composition comprising acompound according to claim 4 and a pharmaceutically acceptable carrier.8. A composition comprising a compound according to claim 5 and apharmaceutically acceptable carrier.